Air conditioner indoor units known in the art blow air (temperature-adjusted air) into an indoor space. Patent Document 1 and other documents disclose an indoor unit of this type. The indoor unit of Patent Document 1 includes a plurality of louvers (wind direction adjusting slats) arranged side by side at its outlet (outlet opening). The louvers are repeatedly turned upward and downward within the largest possible range to improve the air impelling performance and comfort.